1. Field of the Invention
Example embodiments of the present invention relate to a paint composition of cationic electrodeposition and a method of preparing the same. More particularly example embodiments of the present invention relate to a paint composition of cationic electrodeposition which a dried film coated with does not include heavy metals such as lead, tin, etc., and minimizes error rate by prohibiting frictional electricity in assembling electronic parts, and a method of preparing the paint composition of cationic electrodeposition.
2. Description of the Related Art
An electrodeposition paint is used in electronic parts, which require a high rust inhibition while coating an object by electrically educing paint particles. For example, an electrodepositon paint is used in a coating of hard disk drive. As an auxiliary memory device of a computer, a hard disk drive analyzes data stored by a magnetic head or records data in a magnetic disk. A base frame is produced by die casting an aluminum alloy in order to protect a hard disk drive, and coating films are continuously formed on the hard disk drive by electrodeposition coating in order to protect the base frame.
Generally, an electrodeposition paint is a cationic epoxy electrodeposition paint, a cationic acrylic electrodeposition paint, an anionic electrodeposition paint, etc.
In the case an electrodeposition film is coated with a cationic electrodeposition epoxy paint, a dried film includes a lead and a tin to improve corrosion resistance of materials. In conventional processes, a cationic epoxy electrodeposition paint including a lead but excluding a tin is used so as to coat the base frame of a hard disk drive. But according as the restriction of environmental contamination progress rapidly in order to remove or reduce harmful material such a lead etc. from the film of electrodeposition paint composition, the removing of a lead has been required from cationic epoxy electrodeposition paint for use of coating base frame of hard disk drive. Hence, researches to exclude factors that may affect drive performance of a hard disk drive by exposing an aluminum alloy have been actively pursued while removing a lead and a tin from usual base frame film of a hard drive disk. Here, the aluminum alloy results from appearance defect of pin to hole phenomena by generation of hydrogen gas in the case of coating. For example, Korean Patent Laid Open Publication No. 2005-0070495 discloses an electrodeposition paint removing a lead and a tin from a dried film.
When coating electronic parts and metallic materials by utilizing the epoxy electrodeposition paint that does not include tin, frictional electricity may be generated in an assembling process. Here, in case that a hard disk drive is completed, a data loss may be generated.
Accordingly, a paint composition of cationic electrodeposition is needed that the dried film coated with on electronic parts of iron and aluminum alloy dose not includes lead, tin etc., may have a surface resistance and a tribocharge within a proper range and prevent frictional electricity from being generated through anti-static capacity.